Age-related macular degeneration (AMD) is the most common cause of visual loss in older Americans and a leading cause of blindness. Heredity, diet, and environmental factors have been identified as risk factors for AMD in population studies. Genetic linkage studies recently identified loci containing AMD-causing genes on chromosomes 1 and 17. The goals of this proposal are to identify novel genes involved in the pathogenesis of AMD and localize additional genes for this complex trait. Specifically, we propose to refine the localization of AMD-causing genes using allele and haplotype association employing single nucleotide polymorphisms. The refined critical regions will be used as starting points for candidate gene mutation scanning. A genome-wide search for macular degeneration loci will be performed using allele association and a pooling strategy for cost effectiveness. The identification of genetic risk factors for AMD is an important step in understanding the pathophysiology of this debilitating condition.